Frank g



(No Model.)

P. G. BOLLES. ELECTRIC SWITCH.

Patented Nov. 6, 1894.

i i a.

UNITED ,ATENT Fries.

FRANK G. BOLLES, OF WVASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOR OFONE-THIRD TO PAUL EATON, OF SAME PLACE.

ELECTRIC SWITCH.

SPECIFICATION forming part of Letters Patent No. 528,900 datedNovemberfi, 894.

Application filed March 27, 1894.

To all whom it may concern.-

Belt known that I, FRANK G. BOLLES, a citizen of the United States,residing at Washington, in the District of Columbia, have inventedcertain new and useful Improvements in Switches for Controlling ElectricCircuits; and I do declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same, reference being hadto the accompanying drawings, and to the letters of reference markedthereon, which form a part of this stationary terminal, and betweenwhich. the

movable terminal or blade enters. When the switch is of largedimensions, it is sometimes difficult to open it, owing to the greatfriction between these terminals, and the slowness with which the switchmay have to be opened increases the danger of injurious arcing be tweenthe terminals.

My invention consists in a device for tightening the contact between theterminals of an electric switch after the switch is closed, in order toreduce the resistance and insure a more perfect electrical continuity ofthe circuit. r i

The invention is capable of being carried out in a variety of ways, andis applicable to utilized to effect the tightening of the contacts. Inorder to do this, the handle must be movable relatively to the movablecontact or the blade of the switch, and this movement $erial No.505,298. (No model.)

verse to the movement of the movable contact, or in line therewith. Itmay be applied to one or more contacts, and in the latter case, they maybe operated simultaneously or separately as desired.

In the accompanying drawings, Figure 1 is a perspective view of one formof switch embodying my invention. Fig.2 is an end elevation thereof,showing the contacts not tightened. Fig. 3 is an end elevation on alarge scale, showing the contacts tightened. Fig. 4 is a side elevationof Fig. 3. Fig. 5 is aside view of the end of the handle. Fig. 6 is anend elevation of a modified construction. Fig. 7 is a side elevationthereof. Fig. 8is a side elevation of a second modification.

The base A is of some insulating'material, I

such as slate. The bifurcated block B serves as a support or fulcrum forthe movable knife blade contact C, which is shown hinged on a transversebolt D. Passing transversely through the free end of the blade C is abolt E which is rigidly fastened in place, as by the set screw 0.Thestationary contact is a bifurcated block F having space enoughbetween its arms to receive the blade C which fits snugly therein, toclose the circuit, the line terminals being connected to the blocks B,F. Each arm f of the forked block F is notched to receive the bolt E.

On the projecting ends of thebolt is fulcrumed the forked handle G, theyoke of the fork being wide enough to pass down outside of the arms f.The bolt is also equipped at one or both ends with clamping ortightening devices, adapted to be operated by turning the handle, andserving to clamp the arms f tightly against the blade C, thereby greatlyimproving the electrical contact and reducing the resistance of thecircuit.

In Figs. 1 to 5, the ends of thehaudle yok are shown as provided ontheirouter faces with inclined surfaces or planes, preferably two,constituting the cams g g. In contact with these are washers H, eachhavinga corresponding double cam, and locked to the bolt by a spline hentering a keyway in the bolt.

Nuts I engaging with the screw-threaded ends of the bolt enable thewashers to be adjusted toward the arms fin order to increase theclamping action or compensate for wear. Since the washers I-I do notturn on the bolt, there is no tendency to turn. the nuts when the handleis moved.

The handle stands normally as shown in Figs. 1 and 2, with the abruptshoulder g? at the ends of the cams g g abutting against thecorresponding shoulders in the washers, and preventing the handle frombeing moved farther back. Forward movement is, prevented by a pawl Kpivoted to the knife blade 0 and engaging with a pin 9 on the handle. Aspring is may be used to hold the pawl in engagement if desired.

The operation isas follows: When the movablecontact isswung down, itenters between the arms f, and closes the circuit. At the sameztime thepawl islifteclolf the pin g by striking a stop F risingadjacent to theblock armsf tightly against the blade C. Itwillbe seenrthat only averyslight inclination: of the cam surfaces is necessaryto causea-powerfulclampingaction. To open the switch thehandle is lifted, untiltheshoulders ofi'the cams: strike, when the parts willbe soloosenedthattheycan be easily separated, and the pawl K dropping down over the pinas the blade is liftedl If desired, the bolt D on which the blade ishinged maybe fittedwith stationary washers Hf havingcam surfaces, andayokeG' similarly. provided, thezyoke being connected by alink L withthehandle G, so thatthe handle operates a clamping device at each end ofthe movable contact.

In" themodification shown in Figs. 6 and 7, the handle yoke engages withtwo nuts M, the screw-threads on the ends of the bolt E being right-andleft-handed respectively, so that themovement of the handle screws thenuts toward each other, and causes them to clamp the arms f againsttheblade O. The nuts have polygonal peripheries fitting polygonal holesin the: handle yoke, to permit them to be adjusted.

In the modification shown: in Fig. 8, the blad'eG closes on aV shapedstationary contactN, and the handle has one or more hooked cams 0 toengage with a stationary post P and'forcethe blade down tightly into thecontact N.

These are but three of many modifications of my basic idea,and indicatethat it maybe carried out in a number of different ways withoutdeparting from the spirit of my invention.

Havingthus described my invention, what I claim as new is.-

1. A switch for controlling electric circuits,

having a fixed contactand. a movable contact, an operating handle on themovable contact, and movable relatively thereto, and a clamping deviceoperated by an independent movement of said handle for tightening thecontact between the fixed and. movable contacts after the circuits areclosed, substantially as described.

2. A switch for controlling electrical circuits, provided with aclamping device to tighten the contact between its movable andstationary parts, said device being operated by the switchhandleindependently of the movement which it imparts to the movableportion of the switch, substantially as described.

3. A switch for controlling, electrical cirj cuits, having its movablecontact provided with a relatively movable handle, and. a clampingdevicefor tightening thecontact, 5 operated by said.handleindependentlyofthe movable contact, substantially as described.

4. A switch for controlling electrical circuits, having its movablecontact provided with a relatively movable handle, astationary contactwith which the movable contact engages, and a clampingdevice operated bysaid handle independently of the movable contact and serving-to forcetheeontactsto j cuits, having its movable contact provided. with arelatively movable handle, and a transverse bolt, and a clamping devicemovable axially of said bolt andoperated by said handle, serving totighten the contact. between the movable and stationary parts of theswitch, substantially as described.

7. A switch for controlling electrical cir-' cuits, having its movablecontact provided with a relatively movable handle and atransverse bolt,and a clampingdevice comprising two inter-operating inclined planes oneof whichis movable bysaid handle, saidclamping deviceoperating totighten the contact, substantially as described.

8. A switch for controlling electrical circuits, having its movablecontact provided with a relatively movable handleand a transverse bolton which said handle is f-ulcrumed, and two stationary washerson saidbolteach having one or more cam surfaces to cooperate with similarsurfaces on: the end of the handle, substantially as described.

9. A switch for controlling electrical circuits, having its movablecontact provided with a transverse belt, a handle. having a ICC forkedyoke fulcrumed on said bolt, and provided with cam surfaces andshoulders, washers splined on said bolt and having cam surfacescooperating with those on the yoke, and nuts on the bolt to adjust thewashers, substantially as described.

10. The combination with the stationary bifurcated contact block, of themovable contact blade, the transverse bolt, the forked handle fulcrumedthereon, and carrying the cam surfaces, the stationary cam faced washerson the bolt, the pawl pivoted to the movable contact, and the pin on thehandle, substantially as described.

11. In an electric switch, the combination with the movable contact,,ofa handle hinged thereto, and a locking device for locking the handle tothe contact, substantially as described.

12. In an electric switch, the combination with the movable contact, ofa handle movable relatively thereto, a locking device for lockingthehandle to the contact, and means In testimony whereof I affix mysignature in 0 presence of two witnesses.

F. G. BOLLES.

Witnesses:

PAUL EATON,

W. H. BENTLEY.

